Influence of in ovo administered Cryptosporidium baileyi oocyst extract on the course of homologous infection     

Hornok S  Széll Z  Sréter T  Kovács A  Varga I 《Veterinary parasitology》2000,89(4):313-319

In order to evaluate the effect of in ovo vaccination on avian cryptosporidiosis, two doses (1 and 10microg) of Cryptosporidium baileyi oocyst extract (OE) were injected into the amnionic sac of embryonated, specific pathogen-free chicken eggs. After hatching these birds as well as infected controls (IC) were inoculated with 8x10(5) C. baileyi oocysts at 10 days of age. Another group of chickens remained uninfected (UC). Faecal oocyst shedding was measured every second day, and weekly ELISAs were performed to monitor seroconversion. Those chickens that received OE during embryogenesis showed dose-dependent shift in their oocyst shedding, with higher oocyst output of OE1 and OE10 birds compared to IC ones. The patency was significantly longer in the OE10 group than in IC or OE1. ELISA results showed low seroconversion of OE1 and OE10 chickens prior to homologous challenge. Challenge infection resulted in antibody levels without significant difference between IC, OE1 and OE10 groups. These data suggest that in ovo vaccination with C. baileyi oocyst extract does not promote immune response, moreover, it may impair immunity and thus delay the clearance of cryptosporidia from chickens.  相似文献   

Combined Effect of Drought Stress and Elevated Atmospheric CO2 Concentration on the Yield Parameters and Water Use Properties of Winter Wheat (Triticum aestivum L.) Genotypes          下载免费PDF全文

B. Varga  G. Vida  E. Varga‐László  B. Hoffmann  O. Veisz 《Journal of Agronomy and Crop Science》2017,203(3):192-205

The decline in the amount of water available to plants will lend growing importance to the dynamics of water uptake and to water use efficiency (WUE ; g kg^?1) in cereals. Water use properties were investigated in terms of the phenological and yield parameters of five winter wheat genotypes in a greenhouse experiment carried out in climate‐controlled chambers. The plants were grown either with optimum water supplies or with simulated drought in two phenophases, combined with different CO ₂ concentrations (ambient and enriched to 700 and 1000 ppm). Multivariate analysis showed that the CO ₂ concentration alone significantly influenced water use and water use efficiency but in combination with the cultivars, it also had a significant influence on the grain yield and in a combination with the water supply on the straw biomass, respectively. Higher CO ₂ concentration significantly reduced the water uptake and improved the WUE values in both the drought treatments. All three factors investigated were found to have a significant influence on the water consumption during the growing season, and the interaction between CO ₂ and the cultivar influenced WUE . The least change in WUE was detected for Bánkúti 1201 (1.35–1.86 g kg^?1), while Mv Mambó, Plainsman V and Mv Toborzó formed a group responding similarly to various environmental effects (1.85–2.55 g kg^?1; 1.57–2.34 g kg^?1 and 1.45–2.24 g kg^?1, respectively).  相似文献   

Peptide neurotoxins from fish-hunting cone snails   总被引：39，自引：0，他引：39  

B M Olivera  W R Gray  R Zeikus  J M McIntosh  J Varga  J Rivier  V de Santos  L J Cruz 《Science (New York, N.Y.)》1985,230(4732):1338-1343

To paralyze their more agile prey, the venomous fish-hunting cone snails (Conus) have developed a potent biochemical strategy. They produce several classes of toxic peptides (conotoxins) that attack a series of successive physiological targets in the neuromuscular system of the fish. The peptides include presynaptic omega-conotoxins that prevent the voltage-activated entry of calcium into the nerve terminal and release of acetylcholine, postsynaptic alpha-conotoxins that inhibit the acetylcholine receptor, and muscle sodium channel inhibitors, the mu-conotoxins, which directly abolish muscle action potentials. These distinct peptide toxins share several common features: they are relatively small (13 to 29 amino acids), are highly cross-linked by disulfide bonds, and strongly basic. The fact that they inhibit sequential steps in neuromuscular transmission suggests that their action is synergistic rather than additive. Five new omega-conotoxins that block presynaptic calcium channels are described. They vary in their activity against different vertebrate classes, and also in their actions against different synapses from the same animal. There are susceptible forms of the target molecule in peripheral synapses of fish and amphibians, but those of mice are resistant. However, the mammalian central nervous system is clearly affected, and these toxins are thus of potential significance for investigating the presynaptic calcium channels.  相似文献   

Alkylpyridiniums. 2. Isolation and quantification in roasted and ground coffees     

Stadler RH  Varga N  Milo C  Schilter B  Vera FA  Welti DH 《Journal of agricultural and food chemistry》2002,50(5):1200-1206

Recent model studies on trigonelline decomposition have identified nonvolatile alkylpyridiniums as major reaction products under certain physicochemical conditions. The quaternary base 1-methylpyridinium was isolated from roasted and ground coffee and purified by ion exchange and thin-layer chromatography. The compound was characterized by nuclear magnetic resonance spectroscopy ((1)H, (13)C) and mass spectrometry techniques. A liquid chromatography-electrospray ionization tandem mass spectrometry method was developed to quantify the alkaloid in coffee by isotope dilution mass spectrometry. The formation of alkylpyridiniums is positively correlated to the roasting degree in arabica coffee, and highest levels of 1-methylpyridinium, reaching up to 0.25% on a per weight basis, were found in dark roasted coffee beans. Analyses of coffee extracts also showed the presence of dimethylpyridinium, at concentrations ranging from 5 to 25 mg/kg. This is the first report on the isolation and quantification of alkylpyridiniums in coffee. These compounds, described here in detail for the first time, may have an impact on the flavor/aroma profile of coffee directly (e.g., bitterness), or indirectly as precursors, and potentially open new avenues in the flavor/aroma modulation of coffee.  相似文献   

Effect of Simulating Drought in Various Phenophases on the Water Use Efficiency of Winter Wheat          下载免费PDF全文

B. Varga  G. Vida  E. Varga‐László  S. Bencze  O. Veisz 《Journal of Agronomy and Crop Science》2015,201(1):1-9

In Central Europe, drought is the most important limiting factor for autumn‐sown cereals. Due to the decline in groundwater, it is a priority to use less water‐demanding forms of crop production. Water use efficiency (WUE) can only be increased if cultivars with satisfactory water management traits are grown, so that they can exploit the water reserves of the soil even if drought occurs during the vegetation. Water consumption and water use efficiency of winter wheat genotypes were investigated in a model experiment carried out in a climate‐controlled glasshouse. The plants were grown either with optimum water supplies or with simulated drought in three phenophases, and measurements were made on the yield parameters, phenological traits and water use parameters of the plants. Substantial differences were observed between the water demands of the cultivars, and it was found that the later the phenophase in which drought was simulated, the greater the decline in water uptake. The analysis of WUE led to the conclusion that the WUE values of cultivars with short vegetation periods dropped to the greatest extent when water deficit was suffered at first node appearance, while cultivars with longer vegetation periods were more sensitive to drought during the heading and grain‐filling stages.  相似文献   

Phenotypic differences among three clonal lineages of Phytophthora ramorum     

M. Elliott  G. Sumampong  A. Varga  S. F. Shamoun  D. James  S. Masri  N. J. Grünwald 《Forest Pathology》2011,41(1):7-14

There are three major clonal lineages of Phytophthora ramorum present in North America and Europe named NA1, NA2, and EU1. Twenty‐three isolates representing all three lineages were evaluated for phenotype including (i) aggressiveness on detached Rhododendron leaves and (ii) growth rate at minimum, optimum, and maximum temperatures. Closely related species P. foliorum and P. hibernalis were included in phenotypic tests since these species are encountered in nursery surveys for P. ramorum. Isolates from the NA2 and EU1 lineages were the most aggressive and isolates from the NA1 group were the least aggressive. The NA1 lineage of P. ramorum was the most variable in aggressiveness and growth rate. The variability in the NA1 lineage was due to the presence of non‐wild type (nwt) isolates. There was no significant difference in growth rate among NA1 wild type (wt), NA2, and EU1 lineages at any temperature tested. The difference between wt and nwt P. ramorum isolates is discussed.  相似文献   

Genetic control of agronomic traits in alfalfa (<Emphasis Type="Italic">M. sativa</Emphasis> ssp. <Emphasis Type="Italic">sativa</Emphasis> L.)     

Dragan Milić  Slobodan Katić  Đura Karagić  Jelica Gvozdanović–Varga  Sofija Petrović  Jan Boćanski 《Euphytica》2011,182(1):25-33

The objective of this study was to develop diallel population hybrids by crossing selected germplasm and to determine the gene effects and genetic control of yield and yield components using diallel analysis. A complete diallel including reciprocals was made during 2003 and 2004 between five alfalfa cultivars of different geographic origin. For each pairwise cross, five plants were chosen at random from each of the two cultivars (~100 florets per plant) to obtain the F₁ generation. A spaced plant field was established in 2006 which included the five alfalfa cultivars (parents) and their 20 diallel hybrids (F₁). The results of the diallel analysis suggest that the genetic control of major agronomic traits is determined by both additive gene action (accumulation of frequency of desirable alleles represented by significant GCA effects) and nonadditive gene action (complementary gene interactions represented by significant SCA effects). This type of gene action expression in alfalfa also determines the way in which breeding is carried out and brings about changes in the methods used and has given rise to the idea of the semi-hybrid breeding of this crop. The concept involves: breeding alfalfas within the population, identification of heterotic germplasm, and the production of seed of the population hybrid (PH).  相似文献   

Detection of urease-negative Bordetella bronchiseptica from the field     

Khayer B  Rónai Z  Wehmann E  Magyar T 《Acta veterinaria Hungarica》2011,59(3):289-293

Four urease-negative Bordetella bronchiseptica isolates originating from pigs were examined by phenotypic and molecular methods. The phenotypic properties of the isolates were in harmony with the data of the literature, except for the lack of urease activity in conventional tube test, API 20 NE and Diatabs? assays. Using genotypic methods, the urease-negative isolates did not differ from the urease-positive reference strain. They were positive in species-specific and ureC PCR, and all strains showed uniform bands in PCR-RFLP studies of flaA genes. The reason for the lack of urease activity, a characteristic considered species specific for B. bronchiseptica, needs to be studied further. The finding underlines the significance of genotyping when the phenotypic identification of B. bronchiseptica seems questionable.  相似文献   

Analysis of clones of Pinots grown in Hungary by SSR markers     

G. Jahnke  J. MájerP. Varga  B. Szőke 《Scientia Horticulturae》2011

Based on our former experiences 7 Pinot gris, 4 Pinot noir clones and Pinot blanc were analysed in 16 (VVS2, VMC5E9, VMC3D12, VVIM10, VMC5G8, VMCNG1E1, VMC1F10, VMC2H4, VMC8A7, VMC7G3, VVMD28, VrZag21, VrZag79, VMC1C10, VrZag25, Scu06vv) microsatellite loci. A dendogramm was constructed using the shared allele method for the estimates of genetic similarity between pairs, and the neighbour joining method for clustering. Based on our results, it can be established, that the Pinot clones all showed high similarity. The Pinot gris clones bred in Badacsony, Hungary (B. 10, B. 10/5, B. 10/10) formed a group and showed the highest similarity with Pinot gris 34 from Romania. The other Pinot gris clones formed another group with Pinot noir C-162. These clones all originated from Western Europe (Germany, France). These genetic differences could be traced back to the different geographical origin of the different clones.  相似文献   

Investigation of goose mycoplasmas     

Z Varga  L Stipkovits  M Dobos-Kovács  M Sántha 《Archiv fuer experimentelle veterinaermedizin》1986,40(1):105-108

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